I hate
1) when theres litterly 2-3 episodes of transformation JUST transformation (ex. dragonball z)
2) where there's 50+ fillers (ex. naruto)
and those are pretty much the only things that really really bother me lol =D

Recap episodes that tells you what's happened so far in ALL previous episodes. This was done several times in Code Geass.
Fillers ofc.
Squeaky voices. (Aoi, Myself; Yourself.)
Dubbed anime. Rukia's voice dubbed is so freaken annoying i swear to god. Makes me wanna stab.
Re-use of scenes. (Gundam Seed, when launching their gundams. Gotta be a retard not to notice.)
When an entire episode is focused on a character that no-one likes.
When you really get into an anime and the final episode is an absolute croc of shit.

i think fillers are not bad.. anyways.. wad i dislyk most when watching an anime:

- when all the characters lyk the main character [[ lacordadoro]] but i lyk the story though;D
- when the "dying"person wants them to do sumthing, those characters diedie aso want hesitate>.>"
- TOO MANY FLASHBACKS in more den 2 continuous epxd
- transforming >3> [[ lyk shugo chara and sugarsugar rune ]] kinda weird to see those transforming stuffs.. but their still my favsxD

though most of my all-time favs has those things i dislyk.. i still lyk them!!!

1. when they take such a long time to transform, and i'm still wondering why the enemies juz dun attack when they r transforming...
2. actually dubs r ok, but sometimes, the voices become squeaky and it's just so~ weird...
3. girls with squeaky voices...
4. the final episodes r not really endings n there're no 2nd seasons....
i think there're some more but i can't think of them right now...

1. Flashbacks...a few is okay (for the entire series) but three or four during each episode is overdoing it a bit.
2. Those girls always jumping into dangerous situations when all they do is get in the way and forces the guy to rescue them.
3. Fillers...they can kill a show